I was doing whities with my gf’s best friend while she was at work and she ended up sucking lines off my dick. She said she was high and I prolly took advantage of her and is threatening to tell my gf unless I pay her(I'm a trust fund baby). How do I report her to the police while keeping it quiet? My gf’s family and mine are old friends and my parents would probably cut me off if they found out what happened.

You wan report am to Police ba?

Just ignore her, she is just threatening but if She carry out her Threat then it may a time to test if what's between you and your gf will last.

Finally, stop all those extra flings cos the damages they usually cause is far reaching.

I don't have the slightest idea what u re saying.. pls explain

Police no go reason ur matter sef,u just want dash them money.dem go invite her and make her write undertaking not to tell.Why not threaten her by also telling her boy/frd what u ppl did.someone seduce you and you both had consensual se*x.
Abi na Ra*pe u do this one wey u dey fear like cow wey dem want go slaughter ni

you need to properly explain this your story. Its not clear